This invention relates generally to a mat seal device for preventing water from entering an electrical connector through an opening provided for cables to be inserted into the connector.
Mat seals are devices used to prevent water from entering an electrical connector through an opening provided for cables to be inserted into the connector. A mat seal includes a mat of elastic material shaped to fit within and across a correspondingly-shaped opening in one end of an electrical connector housing. An outer peripheral edge seal prevents moisture from passing between an outer periphery of the mat and an inner sealing surface of the connector housing. Cables bearing crimp-style terminals are inserted through cable-sealing cable insertion holes formed in the mat and into terminal locations or “terminal cavities” within the connector housing. The cable insertion holes prevent moisture from passing between an inner periphery of each cable insertion hole and an outer surface of the cable that extends through that hole.
For example, U.S. Pat. No. 5,766,039 issued 16 Jun. 1998 to Abe, discloses such a mat seal device with slits extending through a thickness of the mat from the outer peripheral edge seal of the mat through to each cable-sealing insertion hole to provide a relief for easing insertion of a terminal and cable through each hole. However, to seal the slits a plurality of pressing holes or recesses must be formed in an outer-facing surface of the mat adjacent the cable insertion holes, and a special cover must be fabricated to include corresponding tapered projections that are received into the pressing holes when the cover is snapped into place over an opening in a connector housing into which the mat seal has been received. The cover presses the tapered projections into the pressing holes which forces the pressing holes to enlarge diametrically and elastically deforms portions of the mat surrounding the holes causing the slits to close and seal.
Also, U.S. Pat. No. 6,217,394B1 issued 17 Apr. 2001 to Sugie, discloses a mat seal comprising a plurality of cable-sealing cable insertion holes that each include a corrugated seal portion, i.e., two axially-spaced, radially inwardly-extending integral annular sealing ribs. Each sealing rib has an aperture diameter less than a diameter of a cable to be received in the hole so that each sealing rib will be elastically enlarged when receiving the cable and will constrict around and seal against an outer surface of the cable. But a mat seal device constructed according to the Sugie patent is unable to accommodate terminals of varying configurations and cables of varying diameters without cutting, pinching, or otherwise damaging or distorting the sealing ribs within the cable insertion holes or distorting the mat such that terminals, as they are being inserted, fail to coaxially align with terminal cavities in the connector.
It would be desirable for a mat seal to be able to seal an opening in a connector housing without the aid of specially-designed cover and without breaks along the peripheral edge seal, and without any apertures, other than the insertion holes, that pass completely through the thickness of the mat. It would also be desirable for a mat seal to be able to accommodate terminals of varying configurations and cables of varying diameters without cutting, pinching, or otherwise damaging or distorting the sealing ribs within the cable insertion holes or distorting the mat such that terminals, as they are being inserted, fail to coaxially align with terminal cavities in the connector.